1 files changed, 147 insertions, 0 deletions
diff --git a/clang-r353983/include/llvm/BinaryFormat/MsgPackReader.h b/clang-r353983/include/llvm/BinaryFormat/MsgPackReader.h
new file mode 100644
index 00000000..2d332f53
--- /dev/null
+++ b/clang-r353983/include/llvm/BinaryFormat/MsgPackReader.h
@@ -0,0 +1,147 @@
+//===- MsgPackReader.h - Simple MsgPack reader ------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+///  \file
+///  This is a MessagePack reader.
+///
+///  See https://github.com/msgpack/msgpack/blob/master/spec.md for the full
+///  standard.
+///
+///  Typical usage:
+///  \code
+///  StringRef input = GetInput();
+///  msgpack::Reader MPReader(input);
+///  msgpack::Object Obj;
+///
+///  while (MPReader.read(Obj)) {
+///    switch (Obj.Kind) {
+///    case msgpack::Type::Int:
+//       // Use Obj.Int
+///      break;
+///    // ...
+///    }
+///  }
+///  \endcode
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_MSGPACKREADER_H
+#define LLVM_SUPPORT_MSGPACKREADER_H
+
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstdint>
+
+namespace llvm {
+namespace msgpack {
+
+/// MessagePack types as defined in the standard, with the exception of Integer
+/// being divided into a signed Int and unsigned UInt variant in order to map
+/// directly to C++ types.
+///
+/// The types map onto corresponding union members of the \c Object struct.
+enum class Type : uint8_t {
+  Int,
+  UInt,
+  Nil,
+  Boolean,
+  Float,
+  String,
+  Binary,
+  Array,
+  Map,
+  Extension,
+};
+
+/// Extension types are composed of a user-defined type ID and an uninterpreted
+/// sequence of bytes.
+struct ExtensionType {
+  /// User-defined extension type.
+  int8_t Type;
+  /// Raw bytes of the extension object.
+  StringRef Bytes;
+};
+
+/// MessagePack object, represented as a tagged union of C++ types.
+///
+/// All types except \c Type::Nil (which has only one value, and so is
+/// completely represented by the \c Kind itself) map to a exactly one union
+/// member.
+struct Object {
+  Type Kind;
+  union {
+    /// Value for \c Type::Int.
+    int64_t Int;
+    /// Value for \c Type::Uint.
+    uint64_t UInt;
+    /// Value for \c Type::Boolean.
+    bool Bool;
+    /// Value for \c Type::Float.
+    double Float;
+    /// Value for \c Type::String and \c Type::Binary.
+    StringRef Raw;
+    /// Value for \c Type::Array and \c Type::Map.
+    size_t Length;
+    /// Value for \c Type::Extension.
+    ExtensionType Extension;
+  };
+
+  Object() : Kind(Type::Int), Int(0) {}
+};
+
+/// Reads MessagePack objects from memory, one at a time.
+class Reader {
+public:
+  /// Construct a reader, keeping a reference to the \p InputBuffer.
+  Reader(MemoryBufferRef InputBuffer);
+  /// Construct a reader, keeping a reference to the \p Input.
+  Reader(StringRef Input);
+
+  Reader(const Reader &) = delete;
+  Reader &operator=(const Reader &) = delete;
+
+  /// Read one object from the input buffer, advancing past it.
+  ///
+  /// The \p Obj is updated with the kind of the object read, and the
+  /// corresponding union member is updated.
+  ///
+  /// For the collection objects (Array and Map), only the length is read, and
+  /// the caller must make and additional \c N calls (in the case of Array) or
+  /// \c N*2 calls (in the case of Map) to \c Read to retrieve the collection
+  /// elements.
+  ///
+  /// \param [out] Obj filled with next object on success.
+  ///
+  /// \returns true when object successfully read, false when at end of
+  /// input (and so \p Obj was not updated), otherwise an error.
+  Expected<bool> read(Object &Obj);
+
+private:
+  MemoryBufferRef InputBuffer;
+  StringRef::iterator Current;
+  StringRef::iterator End;
+
+  size_t remainingSpace() {
+    // The rest of the code maintains the invariant that End >= Current, so
+    // that this cast is always defined behavior.
+    return static_cast<size_t>(End - Current);
+  }
+
+  template <class T> Expected<bool> readRaw(Object &Obj);
+  template <class T> Expected<bool> readInt(Object &Obj);
+  template <class T> Expected<bool> readUInt(Object &Obj);
+  template <class T> Expected<bool> readLength(Object &Obj);
+  template <class T> Expected<bool> readExt(Object &Obj);
+  Expected<bool> createRaw(Object &Obj, uint32_t Size);
+  Expected<bool> createExt(Object &Obj, uint32_t Size);
+};
+
+} // end namespace msgpack
+} // end namespace llvm
+
+#endif // LLVM_SUPPORT_MSGPACKREADER_H